In conducting seismic operations in shallow water or near-shore areas, there is a need for a receiver array device which is capable of accurately sensing or responding to seismic vibrations without being unduly affected by water current noise and other noises common to shallow water conditions and tidal zones. In the past, emphasis has been placed upon the use of one or more hydrophones which generally have exhibited poor signal-to-noise ratios to the extent that in severe operating conditions, operations must be suspended for long periods. Geophones have not been used extensively in shallow water areas, since a firm anchor must be established in solid contact with the earth beneath the water in order to accurately sense seismic vibrations. Because of the difficulty of anchoring and setting geophones in place, they have not been used in shallow water seismic operations. Furthermore, in the past, there has been no system which integrated the hydrophone and geophone receivers in the same or common unit or body.
It is therefore desirable to provide for a single seismic receiver array device which can be deployed in near-shore and/or onshore areas and effectively advanced over wide areas to sense seismic impulses and transmit same to a transmitter with maximum efficiency and optimum signal-to-noise ratios. In this connection, the device should either be capable of operating while suspended in water or anchored to the earth or floor beneath the water, but in either mode be stable against undue shifting or twisting in the current and present in any of receivers which are deployed in a spatial configuration so as to produce an optimum signal-to-noise ratio whether through the utilization of a series of hydrophones or geophones or a combination of both. Further, it is important that the device be readily transportable to different locations and therefore should be of compact but durable construction as well as being modular to permit several receiver array devices to be interconnected to produce optimum sensitivity under different conditions of use.